1. Field of the Invention
This invention relates to a mounting structure for an accessory which is mounted on a vehicle engine.
2. Description of the Related Art
A vehicle engine is mounted with accessories such as an alternator, a power steering pump, and an air compressor. The accessories are driven by the rotating power of a crankshaft of the vehicle engine which is transmitted via a V-ribbed belt or a V-grooved belt, a pulley, etc. Thus, the accessories are positioned and held on a cylinder block of the vehicle engine so that the pulley of the crankshaft and the pulleys of the accessories will be held within the same plane.
The accessories such as the alternator are held on the cylinder block of the vehicle engine via accessory mounting brackets. That is, the accessory mounting brackets are fixed at predetermined positions of the cylinder block, and the accessories are supported by and fixed to the accessory mounting brackets.
In mounting the accessories, it is necessary to support the accessories, which are heavy objects, by the accessory mounting brackets with ease and with high accuracy. Various mounting structures for improving work efficiency have so far been proposed (see, for example, JP-A-2001-115852).
The technology described in JP-A-2001-115852 is a technology in which a bracket fixed to a cylinder block is provided with a slit opening upward, a bolt (through-bolt) is inserted into a pair of mounting pieces of an alternator, and the through-bolt is inserted from above the slit to mount the alternator. This technology is recognized as being capable of improving the work efficiency for assembling the alternator to the cylinder block.
With the technology described in JP-A-2001-115852, however, it is necessary to insert the through-holt into the slit after lifting the alternator, which is a heavy object, upwardly of the bracket. Thus, much labor is required. Moreover, after the through-bolt is inserted into the slit, the through-bolt is moved within the slit, and the alternator is fixed at a predetermined position. Thus, there is need to adjust the position of the alternator, which is the heavy object, when fixing the alternator. This technology, therefore, does not necessarily result in an increased work efficiency.
Furthermore, a heavy weight is put on bolt holes at a site where the alternator is fixed, and repeated insertion and removal of the bolt for replacement or maintenance of the alternator may decrease the accuracy of the bolt holes. As a result, it may be difficult to maintain the alternator at the predetermined position with high accuracy, and the coplanarity of the pulley of the alternator and the pulley of the crankshaft may fail to be kept.